vortex_array/arrays/list/vtable/
operations.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use std::ops::Range;
5use std::sync::Arc;
6
7use vortex_scalar::Scalar;
8
9use crate::arrays::{ListArray, ListVTable};
10use crate::vtable::{OperationsVTable, ValidityHelper};
11use crate::{ArrayRef, IntoArray};
12
13impl OperationsVTable<ListVTable> for ListVTable {
14    fn slice(array: &ListArray, range: Range<usize>) -> ArrayRef {
15        ListArray::new(
16            array.elements().clone(),
17            array.offsets().slice(range.start..range.end + 1),
18            array.validity().slice(range),
19        )
20        .into_array()
21    }
22
23    fn scalar_at(array: &ListArray, index: usize) -> Scalar {
24        // By the preconditions we know that the list scalar is not null.
25        let elems = array.list_elements_at(index);
26        let scalars: Vec<Scalar> = (0..elems.len()).map(|i| elems.scalar_at(i)).collect();
27
28        Scalar::list(
29            Arc::new(elems.dtype().clone()),
30            scalars,
31            array.dtype().nullability(),
32        )
33    }
34}